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Climate Promises | Earth Wise

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The United Nations climate change conference that recently took place in Egypt is an annual event.  Last year, the conference was in Glasgow, Scotland, and the participants – heads of state and business leaders – produced a long list of promises aimed at fighting global warming.  How have the countries and companies making those promises done so far?  Unfortunately, not very well.

Participants made pledges for progress in several major areas.

Countries promised to cut greenhouse gas emissions faster, but only 24 countries out of the 140 participants have actually done so.

Countries agreed to expedite the deployment of clean energy and the phasing out of government subsidies for fossil fuels.  There has been considerable progress on green power, but coal use actually reached record highs this year primarily because of Russia’s invasion of Ukraine, which caused natural gas prices to spike.

Countries pledged $100 billion a year to help poorer countries shift to cleaner energy sources.  There has been lots of effort in this area, but the target has not been met and it isn’t clear that all the money is going where it is supposed to.

More than 100 countries pledged to slash methane emissions, but most nations are only getting started.

More than 130 countries pledged to halt and reverse deforestation by 2030.  Deforestation is slowly declining, but not fast enough to meet the goals of the pledge.

An important goal for this year’s climate conference was to try to find a way to not just set admirable and valuable climate goals, but to actually accomplish them.  It isn’t easy, but it is essential.

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Countries Made Bold Climate Promises Last Year. How Are They Doing?

Photo, posted July 25, 2009, courtesy of Wagner T. Cassimiro via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Hybrid Renewable Energy Plants | Earth Wise

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Hybrid renewable energy systems combine multiple renewable energy and/or energy storage technologies into a single plant.  The goal is to reduce costs and increase energy output relative to separate systems taking advantage of common infrastructure and the ability of one renewable energy source having appreciable output while a second one might not at a particular time.

Recently, the largest hybrid renewable power plant in the United States was completed in rural Oregon.  The Wheatridge Renewable Energy Facility combines a wind farm, a solar array, and battery storage.

Plants that include just solar power and energy storage are also called hybrid plants, but the Wheatridge Facility is special because it includes wind power.  The facility comprises a 200-megawatt wind farm, a 50-megawatt solar array, and a 30-megawatt battery system capable of providing power for four hours.  The combined system can provide for the electricity needs of about 100,000 homes.

There are about 140 projects in the United States that combine solar and storage.  There are 14 that combine solar and wind.  There are only four plants – with the completion of Wheatridge – that have wind, solar, and storage.  

Wind and solar energy are generally complementary technologies.  Wind is usually strongest at night while solar, of course, is a daytime source of energy.  Solar and wind plants don’t need to be close together to take advantage of this, but hybrid projects benefit from needing only one grid connection and one lease for land.

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A Clean Energy Trifecta: Wind, Solar and Storage in the Same Project

Photo, posted December 27, 2015, courtesy of Gerry Machen via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

California Offshore Wind | Earth Wise

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California has tremendous potential offshore wind resources.  The state set a preliminary target of 15 GW of offshore wind by 2045 earlier this year and may increase that number to 25 GW.  But installing offshore wind on the West Coast is much more challenging than it is on the East Coast.  The reason is that the ocean floor drops off rapidly on the Pacific Coast and it is simply not practical to attach wind turbines to the sea bottom.  Instead, floating turbine technology will be required.  That is more complicated and more expensive.

Despite the challenges, offshore wind in California is moving forward.  The federal Bureau of Ocean Energy Management announced that the auction for rights to develop waters off central and northern California will be held on December 6.  This will be the first wind auction ever along the U.S. Pacific Coast.

The auction will include three lease areas in the Morro Bay Wind Energy Area and two proposed areas in the Humboldt Wind Energy Area.  Combined, the two areas cover over 370,000 acres and could potentially host over 4.5 GW of wind generating capacity.  The projects developed in these areas are likely to become the first floating offshore wind projects in operation in the U.S.

Apart from the challenges of building floating wind installations, there will be the issue of the electric grid in the proposed regions being able to support the added generation from the wind farms.  Substantial grid upgrades will be needed to accommodate all the power coming from the offshore facilities.  In addition, California offshore wind projects will need to jump-start new supply chains in the U.S.

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Date is set for California offshore wind lease auction

Photo, posted March 24, 2016, courtesy of Andy Dingley / TEIA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Agrivoltaics | Earth Wise

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According to a study last year at Oregon State University, co-developing land for both solar photovoltaic power and agriculture could provide 20% of total electricity generation in the United States with an investment of less than 1% of the annual U.S. budget.  Widespread installation of agrivoltaic systems could reduce carbon emissions by 330,000 tons annually and create more than 100,000 jobs in rural communities.

Agrivoltaics could provide the synergistic combination of more food, more energy, lower water demand, lower carbon emissions, and improved local prosperity.  The problem with agrivoltaics to date is that the existing implementations have used solar arrays designed strictly for electricity generation rather than to be used in combination with agriculture.  They are not that well suited to co-exist with growing crops or grazing animals.

A new project is underway at Oregon State that will help researchers to optimize agrivoltaic systems.  The five-acre Solar Harvest Project is being built at the university’s North Willamette Research and Extension Center in Aurora, Oregon in partnership with the Oregon Clean Power Cooperative. 

The solar array for the project is designed specifically for agrivoltaics research and uses panels that are more spread out and able to rotate to a near vertical position to allow farm equipment to pass through.  The project will allow researchers to study the impact of solar panels on soil health, water use, and plant physiology and yields.

Electricity generated from the 326-kW solar system will be available for purchase by Oregon State and community members. 

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Construction starts on Oregon State agrivoltaics farm that will merge agriculture and solar energy

Photo, posted April 5, 2020, courtesy of Sean Nealon / Oregon State University via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Bitcoin Mining And The Environment | Earth Wise

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Bitcoin mining, the process by which the prominent cryptocurrency is created, is well-known to be energy intensive, but the environmental impact of it has not been extensively studied.  People have described Bitcoin as ‘digital gold.’  A new analysis by researchers at the University of New Mexico has found that Bitcoin mining shouldn’t be compared to gold mining.  It is more appropriately compared to the creation of much more energy-intensive products such as beef, natural gas, and crude oil.

Furthermore, the study found that rather than becoming more sustainable over time, Bitcoin mining is becoming dirtier and more damaging to the climate as long as it relies upon fossil-fuel generated electricity.  Estimates are that in 2020, Bitcoin mining used 75.4 terawatt hours of electricity, which is more electricity than the entire country of Austria, as well as 150 other nations around the world.

The study looked at the economic cost of the air pollution and carbon emissions associated with Bitcoin mining and found that in many instances, the negative economic impact of creating a single Bitcoin is more than what the resultant coin is worth.

Based on the market value of Bitcoins, the cost of climate damage for that value is a little less that that of electricity produced by natural gas and gasoline produced from crude oil, but actually more than that of beef production.

There are multiple cryptocurrencies.  Ether is one that voluntarily switched away from so-called proof-of-work mining.  Whether Bitcoin or others will act similarly absent potential regulation remains to be seen.  Until such time, Bitcoin mining remains an increasingly dirty and damaging business.

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Technology: UNM researchers find Bitcoin mining is environmentally unsustainable

Photo, posted May 11, 2017, courtesy of Komers Real via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Carbon Inequality | Earth Wise

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Everyone contributes to climate change through the generation of greenhouse gas emissions, but individual contributions vary greatly.   A study at the Paris School of Economics has determined that just 1 percent of the population is responsible for nearly a quarter of global carbon emissions growth since 1990.

The study estimated emissions from individuals’ consumption and their financial investments, and also from government spending in their country.  Individuals are responsible for carbon emissions as a result of their own activities, but they also bear their share of responsibility for the emissions of the firms that they own or invest in. 

In 2019, people living in sub-Saharan Africa produced an average of 1.8 tons of CO2 equivalent per capita.  In North America, the average per capita was more than 10 times higher.  Meanwhile, the top 10% of North America’s emitters produced more than 75 tons each.

From 1990 to 2019, the bottom 50% of emitters was responsible for just 16% of emissions growth, while the top 1% was responsible for 23%.  The top 0.1% saw emissions growth of 80%.

The inequality between rich and poor is driven more by inequality within countries than by inequality between countries.  This is particularly true for wealthy countries.  For example, over the study period, the top 1% saw their emissions grow by 26% while emissions actually declined 5-15% among low and middle earners even in wealthy nations.

Economic inequality drives a lot of the dynamics taking place within many countries around the world, and this even applies to pollution and greenhouse gas emissions.

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Global carbon inequality over 1990–2019

Photo, posted December 11, 2017, courtesy of Bernal Saborio via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Global Stilling | Earth Wise

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During the summer of 2021, much of Europe experienced a “wind drought” – wind speeds in many places were about 15% below average.  In the UK in particular, winds were unusually calm and wind energy production was dramatically reduced.

Globally, wind speeds have been dropping by about 2.3% per decade since the 1970s.  In 2019, however, global average windspeeds actually increased by about 6%.  The question is whether a trend of slowing winds – so-called global stilling – is associated with climate change or is just natural variability in action.

Wind results from uneven temperatures in air masses.   Much of the world’s wind comes from the difference between the cold air at the poles and the warm air at the tropics.  Because the Arctic is warming much faster than the tropics, it is possible that winds will continue to decline around the world. 

Another factor people cite is the increase in surface roughness.  The number and size of urban buildings continues to increase, which acts as a drag on winds.

Some models predict that wind speeds will decrease over much of the western U.S. and East Coast, but the central U.S. will see an increase.  Experts do not all agree about what is happening with global winds.  Many believe that the observed changes to date have been within the range of variability.  Furthermore, some places have been windier than usual.

All of this really matters for many reasons.  Europe is increasingly dependent upon wind power as an alternative to fossil fuels.  A 10% drop in wind speed results in a 30% drop in energy generation.   Whatever their cause may be, wind droughts cannot be ignored.

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Global ‘Stilling’: Is Climate Change Slowing Down the Wind?

Photo, posted June 28, 2008, courtesy of Patrick Finnegan via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Decarbonizing Could Save Trillions | Earth Wise

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Scientists have long been calling for a transition to clean energy to prevent catastrophic impacts of climate change.  For much of that time, many people and, specifically, many of those in power, were skeptical of the need to do something about the warming climate.  But even as the facts about the changing climate became increasingly undeniable, there continued to be fears that the transition to clean energy sources would be unacceptably expensive and harmful to the economy.

A recent study published by Oxford University shows that the opposite is true:  a concerted effort to convert to green energy technologies such as solar, wind, and batteries, will save the world enormous amounts of money.

The Oxford study shows that a transition to nearly 100% clean energy by 2050 results in a lower-cost energy system that provides energy access to more people around the world.  The energy transition is expected to save the world at least $12 trillion compared to continuing our current levels of fossil fuel use.

The cost of renewable energy sources has been going down for decades and they are already cheaper than fossil fuels in many situations.  It is expected that they will become cheaper than fossil fuels across almost all applications over time.  Accelerating the transition will allow renewables to become cheaper faster.

The study made use of probabilistic models to estimate the costs of various possible future energy systems based on past data.  Even the most pessimistic models showed that scaling up green technologies is likely to drive their costs down so far that they will generate net cost savings and that the faster the transition goes, the more will be saved.  The result will be a cleaner, cheaper, more energy secure future.

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Decarbonising the energy system by 2050 could save trillions

Photo, posted July 12, 2010, courtesy of Tom Shockey via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Electrifying Delivery Vehicles | Earth Wise

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Most of the buzz about electric vehicles relates to passenger cars as the auto industry is making a major transition away from gasoline power.  Recently, pickup trucks have started to get some attention as well as Ford’s electric version of the F-150 truck has hit the streets and the long-awaited Tesla Cybertruck will be introduced next year.  There hasn’t been as much talk about delivery vehicles, but there should be.

There are about 15 million delivery vehicles in the U.S., and they are a significant contributor to greenhouse gas emissions.   The post office alone has a quarter million of them.  Such vehicles are especially attractive candidates for electrification.  Most travel relatively consistent and short routes, which makes it easier for companies to be able to charge them and keep them charged.

Electrifying delivery vehicles in cities is especially important because the vehicles travel into and through residential neighborhoods, spreading pollution and particulates as they go.

Some provisions of the Inflation Reduction Act provide credits for the purchase of commercial vehicles.  Light-duty vans and trucks qualify for a credit of as much as $7,500.  Medium- and heavy-duty trucks qualify for credits as high as $40,000.  In addition, substantial tax credits are available for the installation of charging equipment.

According to a study by the Rocky Mountain Institute, sixty percent of new truck sales could be electric by 2030.  By 2035, the trucking industry could cut its emissions in half.

American companies are already stepping up to the plate.  Amazon plans to deploy 100,000 electric delivery vehicles from new automaker Rivian.  Walmart, UPS, FedEx, and others have also committed to electrified trucks.

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The Climate Bill Will Electrify More Delivery Vans and Trucks

Photo, posted August 1, 2021, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Prospects For Floating Solar | Earth Wise

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Countries are trying to figure out how to get enough energy from solar and wind generation to completely decarbonize their economies.  According to some estimates, nations might have to devote between half a percent and five percent of their land area to solar panels to get the job done.  Half a percent is about the amount of the U.S. that is covered by paved roads.  While there is lots of open land in many parts of the country, covering it with solar panels might not be acceptable to farmers, conservationists, or other interested parties.

One way to deploy more solar panels without using up land is the use of floating solar panels.  Floating photovoltaic systems – also known as floatovoltaics – are becoming increasingly common, especially in Asia.  This year, China installed one of the largest floatovoltaic systems in the world on a reservoir near the city of Dezhou.

Floating solar panels stay cooler and run more efficiently than those on land.  The panels also help prevent evaporation from their watery homes and the shading they provide also help to minimize algal blooms.  Solar installations on reservoirs generally puts them near cities, making it easier to feed power into urban grids.

On the other hand, floating solar systems need to be able to withstand water and waves and are generally more expensive to build than land-based systems.

At present, the installed global capacity of floating solar is only about 3 gigawatts, compared with more than 700 gigawatts of land-based systems. However, reservoirs around the world collectively cover an area about the size of France.  Covering just 10 percent of them with floating solar could produce as much power as all the fossil-fuel plants in operation worldwide.

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Solar Takes a Swim

Photo, posted March 7, 2019, courtesy of Hedgerow INC via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Cleaning Up Urban Rivers With Nature’s Tools | Earth Wise

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Fifty years after the passage of the Clean Water Act, urban waterways across the United States are continuing their comeback and are showing increasing signs of life.  A strategy that is being adopted in many places is to use natural restoration techniques focused on bolstering plants and wildlife to improve water quality.

A nonprofit called the Upstream Alliance has focused on public access, clean water, and coastal resilience in the Delaware, Hudson, and Chesapeake watersheds.  Working with the Center for Aquatic Sciences and with support from the EPA and the National Fish and Wildlife Foundation, the alliance has been repopulating areas of an estuary of the Delaware River near Camden, New Jersey with wild celery grass, which is a plant vital to freshwater ecosystems.

In many places, scientists, nonprofits, academic institutions, and state agencies are focusing on organisms like bivalves (typically oysters and mussels) along with aquatic plants to help nature restore fragile ecosystems, improve water quality, and increase resilience.

Bivalves and aquatic vegetation improve water clarity by grounding suspended particles, which allows more light to penetrate.  These organisms also cycle nutrients both by absorbing them as food and by making them more available to other organisms.

Underwater restoration projects have been underway in New York Harbor for more than a decade, where the Billion Oyster Project has engaged 10,000 volunteers and 6,000 students. 

The hope is that bringing back bivalves and aquatic plants can create a lasting foundation for entire ecosystems.  It is restoring nature’s ability to keep itself clean.

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How Using Nature’s Tools Is Helping to Clean Up Urban Rivers

Photo, posted December 19, 2019, courtesy of Scott via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

California Climate Legislation | Earth Wise

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At the end of its summer session, California’s state legislature passed five climate-related bills including ones that it had been unable to pass in previous sessions.  Taking all of these actions puts California in the position of blazing a trail for the country and the rest of world in taking aggressive action on climate issues.

One bill confirmed California’s goal of reaching net-zero emissions by 2045.  Another bill added interim-term targets to go along with the state’s goal of 100% renewable electricity by 2045.  It sets a target of 90% by 2030 and 95% by 2040.  That bill mandates that California state agencies use 100% clean energy by 2035, which is a decade earlier than the previous requirement.

A third bill requires the California Air Resources Board to determine steps and regulations for carbon-capture and storage projects at pollution hotspots like oil refineries.

A fourth bill requires the state to set goals for removing carbon dioxide from the atmosphere through natural means such as tree planting.

The California state budget includes a record-breaking $54 billion to be spent on climate programs over the next five years, including $6.1 billion toward electric vehicles, $14.8 billion towards public transit projects, more than $8 billion for electric grid stabilization, $2.7 billion towards preventing wildfires, and $2.8 billion towards managing drought.

California has been dealing with ongoing drought and numerous wildfires and is highly motivated to take decisive action in dealing with the climate crisis.  California’s environmental initiatives often result in comparable actions taken by other states.

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California Passes Massive Climate Legislation Package

Photo, posted March 16, 2019, courtesy of Raymond Shobe via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Green Steel | Earth Wise

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The Inflation Reduction Act provides $369 billion in investments to ramp up renewable energy generation and manufacturing of solar panels, wind turbines, energy storage, and electric vehicles. 

Every megawatt of solar power deployed requires 35 to 45 tons of steel.  Every megawatt of wind power uses 120 to 180 tons of steel.   Estimates are that it will take 1.7 billion tons of steel just to build all the wind turbines needed to reach net zero emissions by 2050.

This is a big problem because steel production accounts for roughly 10% of global carbon emissions and is one of the most carbon-intensive industries in the world.

Making steel is a complex and age-old process that hasn’t changed much over time.  Green steel is steel made with little or no carbon emissions.  There are a few ways to do it.  One is called the direct reduced iron method that uses green hydrogen instead of fossil fuel gas to produce iron and then a renewable-powered electric arc furnace to make the steel. 

Molten Oxide Electrolysis is an alternative green steel approach that doesn’t depend on having a green hydrogen infrastructure.  It uses electrolysis, powered by renewable energy, to separate the bonds of iron ore and produce liquid metal while releasing only oxygen in the process.

Green steel solutions rely on the availability of renewable energy, but the ultimate success of renewable energy will depend on the success of green steel.  The U.S. steel industry will leverage about $6 billion under the Inflation Reduction Act to make progress on it.

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Building tomorrow’s clean energy systems on green steel

Photo, posted October 30, 2008, courtesy of Paul Bica via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Banning Gas-Powered Cars | Earth Wise

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In June, the European Union voted to ban the sale of new gas- and diesel-powered vehicles starting in 2035.   The EU joined Canada, the United Kingdom, Japan, South Korea, and several other countries in imposing future gas car bans.

Here in the U.S., on August 25th, California adopted rules banning the sales of new gas-powered cars and light trucks by 2035.  New York passed a similar law last year and its ban will also cover heavy trucks by 2045.

California’s action is particularly significant because there are other states that have trigger laws that impose their own bans based on what California does.  Washington state, Massachusetts, and Virginia are in this category, although the governor of Virginia has said he plans to try to repeal the law.

An additional 12 states have policies tied to California’s and are likely to adopt their own versions of the 2035 ban.  These are Colorado, Connecticut, Delaware, Maine, Maryland, New Jersey, New Mexico, Nevada, Oregon, Pennsylvania, Rhode Island, and Vermont.

When these regulatory actions are coupled with the major investments in electric vehicles being made by virtually all automakers, the transition to electric vehicles appears to be inevitable.

As far as people who love their gas-powered cars are concerned, the new rules only apply to new car sales.  So, consumers can still buy and own used cars that run on gasoline.  If there are states that never impose bans on new gas-powered vehicles, then consumers can go to those states and buy one, assuming there are any being made at that point.   It seems likely that gas-powered cars will end up being made for hobbyists and aficionados only. 

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California Just Banned Gas-Powered Cars. Here’s Everything You Need to Know

Photo, posted May 20, 2018, courtesy of James Loesch via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Low Fares Clean German Air | Earth Wise

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Germany’s parliament set summer public transport fares at 9 euros a month as a way to slash pollution and reduce imports of Russian oil.   The low price included all buses, trams, subways, and regional trains, effectively lowering prices by more than 90% in some cities.  Berliners saved 98 euros on their monthly travel pass; commuters in Hamburg saved even more.

The program began June 1 and ended August 31.  The bargain rates drove widespread use of public transport and discouraged the use of cars, which already was undesirable due to high gasoline prices.   Over the three-month period, transit authorities sold over 50 million subsidized tickets.  One out of five travelers were using public transport for the first time, according to surveys.

According to an estimate from the Association of German Transport Companies, the program helped to avoid 1.8 million tons of carbon dioxide emissions.  This is roughly equivalent to taking 1.5 million cars off the road for the summer or planting 30 million trees.

The discount transit program had a clearly positive effect on the climate and, obviously, was a source of financial relief for German citizens.  Last year, Germany was the largest buyer of Russian oil in Europe and it wanted to make drastic reductions in its purchases.  The success of the program prompted many to ask for it to be continued.  However, the program cost the government about 2.5 billion euros in reimbursements to transit companies.  The German government has said it would not be extended.

Nonetheless, German policymakers are weighing other proposals for low-cost public transit.  Clearly encouraging people to use public transit pays dividends.

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Germany’s Cheap Summer Train Fares Prevented 1.8 Million Tons of Carbon Pollution

Photo, posted June 6, 2022, courtesy of 7C0 via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Colorful Solar Panels | Earth Wise

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More and more buildings and public spaces are incorporating solar panels and not only just on rooftops.  Some buildings are incorporating power-generating structures all over their facades.

Using solar panels in this way puts some design constraints on buildings because solar panels are typically a deep black color.  This is because solar panels need to absorb light and making them any other color decreases their ability to do so and generate power.  But the problem is that people don’t necessarily want a black building.

One alternative to traditional solar panel design is to use structural sources of color that include microscopic shapes that only reflect specific light frequencies, like the scales on butterfly wings.  But this approach generally leads to iridescence – which might not be what is wanted – and is often quite expensive to implement.

A team of researchers at a university in Shanghai has now demonstrated a way to give solar panels color that is easy and inexpensive to apply and that does not reduce their ability to produce energy efficiently.

The technique involves spraying a thin layer of a material called a photonic glass onto the surface of solar cells.  The photonic glass is made of a thin, disorderly layer of dielectric microscopic zinc sulfide spheres.  Even though most light can pass through the photonic glass, certain colors are reflected back, depending on the sizes of the spheres.  By varying that size, the researchers created solar panels that were blue, green, or purple with only a very small drop in solar panel efficiency.

The solar panels made this way maintained their color and performance under durability testing.  With this new technology, there may soon be colorful solar panels on our buildings.

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Colorful solar panels could make the technology more attractive

Photo, posted December 15, 2021, courtesy of Pete via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Propane Refrigerants | Earth Wise

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About 10% of the world’s total electricity supply is used for air conditioning.  If current temperature trends continue, the energy demands for space cooling will more than triple by the year 2050.  Air conditioning is a double threat to the environment.  Apart from using lots of energy, ACs also make use of halogenated refrigerants that are extremely powerful greenhouse gases.

The most common space cooling appliances are split-air conditioners, which use an indoor unit and an outdoor unit connected by pipes.  These split ACS mostly utilize HCFC-22 and HFC-410 as refrigerants, which have global warming potential scores as high as 2,256 – meaning they trap 2,256 times more heat than carbon dioxide. 

A study by the International Institute of Applied Systems Analysis in Austria has shown that propane is a far better choice as an air conditioning refrigerant.  Its global warming potential is actually less than 1 meaning it traps less heat than carbon dioxide.  According to the study, if air conditioners switched to propane refrigerants, the world would avoid about a tenth of a degree Celsius of additional warming, which is a significant contribution to meeting the goals of the Paris climate agreement.

Propane-based split-ACs are already available commercially in China and India.  Elsewhere, many national regulations prohibit their use, primarily due to codes restricting the use of refrigerants with higher flammability.  Given the increasingly urgent need for climate action, it seems to be time to reconsider regulations on refrigerants.

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Propane — a solution for more sustainable air conditioning

Photo, posted March 24, 2021, courtesy of Phyxter Home Services via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Pumped Hydro Storage In Switzerland | Earth Wise

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Pumped hydro energy storage is still by far the largest form of energy storage in the world, representing more than 90% of storage capacity worldwide.  The theory behind it is simple.  Water is pumped into an upper reservoir (that is, one at a higher elevation), and when electricity is needed, the water is allowed to flow downhill to power turbines and then is collected in a lower reservoir.   When there is excess electricity, it is used to pump water back uphill for use later.

Pumped hydro installations can’t be built just anywhere.  Geography and hydrology have to be suitable, which means high voltage transmission lines need to be constructed to link electricity sources like wind and solar farms with the storage location.  But in those situations where pumped hydro makes sense, it is a great solution to the energy storage problem.

Switzerland has just completed one of the largest pumped hydro facilities in the world.  The Nant de Drance installation makes use of the Emosson reservoir, which is an artificial lake built high in the Alps near the French border.  Over the past 14 years, 10 miles of tunnels have been dug into the mountains to connect the Emosson reservoir to the Vieux Emosson reservoir to the south.

In between the two reservoirs is a giant underground cavern where six of the largest water-driven turbines in the world are spun from the water rushing down from above.  The turbines have a capacity of 900 megawatts, making Nant de Drance one of the most powerful generating plants in Europe.  In terms of storage capacity, the installation has a maximum capacity of 20 gigawatt-hours, and can store that energy indefinitely, which is challenging for other storage technologies.

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14 Years In The Making, 20 GWh Pumped Hydro Storage Facility Comes To Switzerland (With Video)

Photo, posted September 7, 2009, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Cheap Material For Carbon Capture | Earth Wise

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The recently passed Inflation Reduction Act includes significant support for carbon capture technologies. Eliminating fossil fuel burning is essential for halting climate change, but in the interim, methods for capturing emissions of carbon dioxide and either storing it or turning it into usable products are increasingly necessary.

There are a variety of techniques being developed for carbon capture but at this point, none of them are commercially viable.  The best technique in use today involves piping flue gases through chemicals called liquid amines, which bind CO2.  The process requires large amounts of energy to release the bound carbon dioxide so it can be concentrated and stored.  As a result, it is complicated and expensive.

Researchers at UC Berkeley, Stanford, and Texas A&M University have developed a carbon capture method using melamine, which is an inexpensive polymer used to make Formica, as well as low-cost dinnerware, industrial coatings, and other plastics.  Porous melamine itself adsorbs CO2 to a limited extent.  But the researchers discovered that adsorption could be much improved by adding the chemical DETA (diethylenetriamine) to bind the CO2.  In addition, adding cyanuric acid increased the melamine pore size and radically improved CO2 capture efficiency even more.

The result is a material that is more efficient even than exotic carbon capture materials like metalorganic frameworks and is much cheaper and easier to make. The researchers aim to design equipment that can used in industrial facilities, attached to buildings and other structures, or even to the tailpipes of gas-powered vehicles.

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A simple, cheap material for carbon capture, perhaps from tailpipes

Photo, posted June 10, 2006, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Solar Windows | Earth Wise

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Solar windows are an attractive idea.  It is very appealing to have the vertical surfaces on the outside of almost any building generate electricity.  The challenge is to have a transparent window be able to function as an efficient-enough solar panel.

Most conventional solar panels use silicon solar cell technology, which is not based on a transparent material.  Transparent solar cells use dye-sensitized technology, which has been the subject of research for decades but has yet to achieve widespread use.

Researchers at the University of Michigan have recently published work on a new process to manufacture solar windows that can be large (over six feet in each dimension) and efficient at electricity production.

The windows make use of dye-sensitized cells which are connected to lines of metal so small that they are invisible to the naked eye.  The individual cells are fairly small but the connection technology allows the construction of large windows.

The solar window has an efficiency of 7%, meaning 7% of incoming sunlight energy is converted to electricity.  The researchers believe that 10% efficiency should be attainable with their technology.  Conventional solar panels have efficiencies of 15% or more.

However, the goal is not necessarily to compete with silicon solar panels.  The real opportunity is to be able to generate electricity when rooftop solar is not practical or to produce additional electricity even when there is already a solar roof.

Going forward, the goals of solar window development are to increase efficiency and to reduce costs to where installing the windows is economically attractive.  Estimates are that the windows currently would cost about twice as much as a conventional window but would pay for the difference in two to six years depending on such things as the level of sun exposure.

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Web Links

Inside Clean Energy: What’s Hotter than Solar Panels? Solar Windows.

Photo, posted April 17, 2017, courtesy of Shelby Bell via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

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